Objects in PHP

Anon

I wrote the following Object:

<?
class User {
var $userID, $userName;

function User($inputUserID) {

require("dbconnector.php");
$result = @mysql_db_query($db, 'select USERID, USERNAME from USER where USERID = $inputUserID');

$row = @mysql_fetch_row($result);

$this->setUserID($row[0]);   
$this->setUserName($row[1]);

}

function getUserID() {
return $this->$userID;
}

function getUserName() {
return $this->$userName;
}

function setUserID($newUserID) {

$this->$userID=$newUserID;
}

function setUserName($newUserName) {

$this->$userName=$newUserName;
}
}
?>

and in a different file, I try to instantiate that object with the following code:

<?
require("user.php");

    $user = new User(1);
    echo $user->userID;         
    echo $user->userName;

I get a big ole blank. Any thoughts? I'm an experienced Java OO guy trying to teach himself this hot new php stuff...

Anon

These functions/methods are wrong:

function getUserID() {
return $this->$userID;
}

function getUserName() {
return $this->$userName;
}

function setUserID($newUserID) {
$this->$userID=$newUserID;
}

function setUserName($newUserName) {
$this->$userName=$newUserName;

}

try this:
function getUserID() {
return $this->userID;
}

notice there is no \'$\' preceeding the member var name..

hth.
p.

daarius

and secondly, you cant access the attributes of class directly, without first initialising them by using setUserID() etc. methods.

why dont you use getUserID()? instead of calling the attribute?

Anon

Ok, I understand the removing of the '$' symbols, and am now calling my getUserID() methods...but nothing shows up and there's no errors...here's some updated display code, please see the original message for the object code:

<?
require("user.php");

    $user = new User(1);
    echo $user->getUserID();  
    echo $user->getUserName();

Anon

notice that the code snippet below shows that accessing the member variables is possible outside the class b/c php does not allow you to limit scope w/in your class like Java/C++. You aren't required to use set and get methods to assign/retrieve data, but it is certainly better practice (borrowed from Java?).

class attributeTest {
var $attributeOne;
var $attributeTwo;

function attributeTest() {
$this->attributeOne = "one";
$this->setAttributeTwo("two");
}

function setAttributeOne($strVal) {
$this->attributeOne = $strVal;
}

function setAttributeTwo($strVal) {
$this->attributeTwo = $strVal;
}

function getAttributeOne() {
return $this->attributeOne;
}

function getAttributeTwo() {
return $this->attributeTwo;
}
}

$attTest = new attributeTest();
print $attTest->getAttributeOne()."<br>\n";
print $attTest->attributeTwo;

Anon

without knowing what is in dbconnector.php and any mysql errors that may be generated, it's tough to help.

take off the @ in front of your mysql functions for now, and add them back when it is working..

Anon

Here's the contents of dbconnector.php, I was just trying to make things cleaner by throwing all the connection stuff in a separate file...obviously I replaced the real database information with mock data...

<?
$db = 'databaseName';
$dbHost = 'hostName';
$dbUsername = 'userName';
$dbPassword = 'password';

    mysql_pconnect($dbHost, $dbUsername,  $dbPassword);
    mysql_select_db($db);

Thanks...

Anon

You seem to be using mysql_select_db() and mysql_db_query. In order to avoid putting an extra parameter(the db name) into all your queries, use mysql_query instead.

I.E.
$iConnection = mysql_pconnect($dbHostname, $dbUsername, $dbPassword);
mysql_select_db($db);
$strQuery = "SELECT * FROM table_name";
mysql_query($strQuery, $iConnection);

The design of this class seems to be off as well, since every time you create a user object, you will be making another connection to the database. Try making the connection in your PHP script before you create the User object. If you want to reuse all the database stuff, I would suggest creating a class (i.e. dbConn) and using mehods like createConnection(), getConnection(), setConnection() all just to handle the connecting to the database..

have methods in the User class like setConnection(), getConnection(), and releaseConnection()

so you could do
$objDBConn = new dbConn();
$objDBConn->createConnection();

$objUser = new User($iUserID, $objDBConn->getConnection());
print $objUser->getUserName();
$objUser->releaseConnection();

I would be wary of doing a "require" inside of a php class. While this may work (I'm not sure if it does), it certainly isn't good practice.

did you remove the "@" before your mysql calls to verify that no errors were returned?

Anon

Thanks a bunch. I used your suggestion with
mysql_query rather than mysql_db_query and it seems to work.

My next move is to create the dbconnection class you suggested...

Yes, I removed the '@' sign from my functions and found the error was an invalid $result, which was fixed with your MySQL function solution. : )